One strain of French structuralism has argued for the existence of long-run economic cycles driven by Marxist class and economic dynamics. Vincent Carpentier employs this approach in his study of the relationship between economic and educational change in the United Kingdom over the past two centuries. The basic framework was developed by Carpentier's mentor, Louis Fontvielle of the University of Montpellier, who has used it to examine the same relationship for France. According to this framework, leading modern economies such as those of France and the United Kingdom over the past two centuries have experienced four Kondratieff cycles of 50 years duration each. During the first three cycles, the level of resources devoted to education tended to move counter-cyclically; in the fourth cycle, the relationship reversed to move pro-cyclically. Fontvielle's explanation of this pattern is that during the first three cycles, during expansionary phases, high returns to physical capital implied pressures to cut back on public educational investments while during downturns, social stresses and contradictions in the system led to expanding educational investments. However in the fourth cycle, since 1945, both the rise of the welfare state and the increasing contribution of an educated labor force to productivity due to the increasing importance of science-based technical change resulted in the level of educational investments moving pro-cyclically.